In recent years, communication systems including a transmitter provided with a bit-interleaved coding and modulation (BICM) encoder have been proposed (e.g. Non Patent Literature 1).
A BICM encoder performs the following steps, for example:
(1) encoding data blocks by using quasi-cyclic low-density parity-check (QC-LDPC) codes, for example;
(2) bit-interleaving the codeword bits obtained by the encoding, which includes parity interleaving and column-row interleaving;
(3) demultiplexing the bit-interleaved codewords to obtain constellation words. The demultiplexing includes processing equivalent to permutation of columns of an interleaver matrix used in the column-row interleaving when 16QAM, 64QAM or 256QAM, for example, are adopted as the modulation scheme; and
(4) mapping the constellation words onto constellations.